The present invention relates to methods of identifying positions of wheel modules included in wheels and/or their associated tires; for example, to a method of identifying positions of wheel modules operable to monitor characteristics of wheels and/or their associated tires and conveying information indicative of these aforementioned characteristics via a communication link to an electronic control unit (ECU) and/or control system, for example for user-display. Moreover, the present invention also concerns wheel modules for use in implementing aforementioned methods. Additionally, the invention relates to methods of servicing vehicles including such wheel modules. Furthermore, the present invention also relates to software and software products executable on computing hardware for executing these aforesaid methods. Tyres, also known as “tires” in American-English, are critical components in road vehicles. Contemporary tires not only ensure adhesion of their associated road vehicles to road surfaces in widely varying weather conditions, but also perform vibration and shock isolation functions. Moreover, during their operating lifetime, tires are required to survive potentially up to several thousand or even millions of deformation cycles without exhibiting work-hardening failure, and yet exhibit a relatively modest degree of energy dissipation therein as a result of viscous dampening effects. As an additional operating requirement, contemporary tires need to be robust against scuffing and objects impacting thereonto. Yet further, tubeless tires are required to robustly grip onto their associated wheel hubs even when subject to considerable stresses, for example during emergency braking. In response to these aforementioned requirements for contemporary tires, the tires are constructed from elastic synthetic rubber, natural rubber and/or plastics material reinforced by meshes of metal wire, carbon fibre and similar. Modern tires are therefore to be respected as highly optimized and advanced products.
Tire failure during operation can potentially result in immobilization of an associated vehicle or even accident. Moreover, tires operated at unsuitable pressures can adversely influence associated vehicle fuel economy; fuel economy is becoming increasingly pertinent in view of increases in fuel costs as well as in view of carbon dioxide generation and its perceived impact on World climate change.
It is known to mount sensors onto automobiles to monitor characteristics such as tire pressure and acceleration in one or more orthogonal axes, and to convey information representative of these characteristics via wireless communication links to electronic control units (ECU) forming parts of data management systems of the vehicles. By employing such arrangements, it is possible to warn drivers of a need to inflate one or more tires of their vehicles in order to improve driving quality and safety.
In a published Japanese patent no. JP 2003211924 (Mazda Motor), there is a disclosed a pneumatic sensor device suitable for use with a tire of a vehicle for detecting tire pressure and generating corresponding tire pressure information. The device includes a transmitter for transmitting the pressure information together with an identification code for distinguishing the sensor device from other such sensor devices simultaneously included on other wheels of the vehicle. A control unit of the vehicle is operable to receive the transmitted pressure information and its associated identification code. The received pressure information is stored in a memory of the control unit. The control unit is operable to raise an alarm in an event that tire pressure is not correct pursuant to predefined criteria.
In a published United Kingdom patent application no. GB 2385931 A, tire monitors are described which are mounted adjacent to tires near their tire inflation valve stems. The tire monitors include sensors to measure pressure, temperature and rotation direction of their respective tires. Moreover, the monitors are operable to communicate measured sensor signals via transmitters to their respective receiver for subsequent processing and eventual presentation on a display unit. A vehicle mounted controller in communication with the receiver is operable to determine whether pressure information is associated with a front tire or a rear tire based on the strength of the wireless signal received at the receiver, and whether pressure data is associated with a right tire or left tire based on associated rotation direction data.
On account of tire condition being an important factor influencing vehicle operating economy and safety, a technical problem is therefore how to provide more advanced wheel and tire monitoring. When a fleet operator has many vehicles in its fleet, ensuring quality of wheel and tire maintenance for all the vehicles in the fleet is paramount. Such quality can at least partially be ensured by following rigorous manual maintenance routines, for example by performing regular vehicle inspections and systematically changing tires after a predefined number of travelled kilometers. However, it is still feasible that tires and wheels undergo events which escape the attention of such rigorous maintenance routines and can therefore represent a potential hazard. For example, wheels are potentially exchanged between vehicles either without authorization of respective vehicles owners which can thereby circumvent such rigorous maintenance routines or by way of theft. Moreover, wheel hubs are susceptible over their operating lifetime to being provided with numerous replacement tires.
As elucidated in the foregoing, tire monitors are known. In order to measure tire condition and detect unauthorized tampering with tires, for example when wheels are temporarily removed from their associated vehicles, for example when exchange from winter tires to summer tires in Northern Europe and Canada, more advanced tire and wheel monitors are required. However, there then arises a technical problem regarding how to manage complex configurations of tire and wheel monitors, especially when tires are replaced at mutually different times and wheels and their tires are susceptible to being retained in storage over periods when exchanging between summer and winder tires.
The present invention seeks to address the aforementioned technical problems.
It is desirable to provide an improved method of identifying locations of wheel and/or tire monitors included in apparatus of vehicles which is capable of enhancing safety and reliability of such vehicles.
A method according to the first aspect of the invention there is provided a method of identifying locations of one or more modules of an apparatus implemented in a vehicle for monitoring operation of at least one wheel of the vehicle, said apparatus including one or more sensor modules operatively mounted to revolve with said at least one wheel, said one or more modules being operatively coupled in communication with a processing arrangement of said vehicle, said one or more modules being operable to determine at least one physical parameter of said wheel and to generate at least one corresponding sensor signal for said processing arrangement, said processing arrangement being operable to process said at least one sensor signal to compute information indicative of operation of said at least one wheel, characterized in that said method includes steps of                (a) communicating with one or more modules of said apparatus for receiving their identification codes at a processing arrangement of said apparatus, said one or more modules being mounted on at least one wheel of said vehicle;        (b) driving said vehicle around a curved trajectory as sensed by said steering sensing arrangement and recording a direction of steering of said vehicle together with a temporal record of said physical parameter determined by said one or more modules together with their corresponding identification codes, said physical parameter pertaining to one or more tires of said at least one wheel; and        (c) applying an analysis to said steering direction and said temporal record in respect of time to identify where said one or more modules are located on said at least one wheel of said vehicle, said analysis utilizing a characteristic that tires on an outside of said curved trajectory will experience different values in said temporal record of said physical parameter than tires on an inside of said curved trajectory, and that tires towards a front region of said vehicle experience a change in the temporal record of said physical parameter before and/or at a higher rate than tires towards a rear region of said vehicle for a forward direction of travel of vehicle.        
The invention is of advantage in that it provides a simple practical method of identifying the locations whereat the one or more modules of the apparatus are located on wheels of the vehicle.
Optionally, there is provided a method of identifying locations of one or more sensor modules of an apparatus implemented in a vehicle for monitoring operation of at least one wheel of the vehicle, the sensor modules operatively mounted to revolve with the at least one wheel, the one or more modules being operatively coupled in communication with a processing arrangement (ECU) of the vehicle, the one or more modules being operable to sense at least one physical parameter of the wheel and to generate at least one corresponding sensor signal for the processing arrangement, the processing arrangement (ECU) being operable to process the at least one sensor signal to compute information indicative of operation of the at least one wheel,
characterized in that the method includes steps of:
                (a) driving the vehicle around a curved trajectory as sensed by a steering sensing arrangement and recording an angle of steering of the vehicle together with a temporal record of lateral accelerations (Az) measured by the one or more modules together with their corresponding identification codes (ID); and        (b) applying an analysis to the steering angle and the temporal record in respect of time (t) to identify locations whereat the one or more modules are located on the at least one wheel of the vehicle, the analysis utilizing a characteristic that accelerometers located on an outside of the curved trajectory will experience greater lateral accelerations during the curved trajectory in comparison to a straight trajectory than accelerometers located on an inside of the curved trajectory, and that accelerometers located towards a front region of the vehicle experience an increase in lateral acceleration temporally before accelerometers located towards a rear region of the vehicle for a forward direction of travel of vehicle during execution of the curved trajectory.        
In this method the physical parameter is constituted by a lateral acceleration measured directly by a sensor arranged in the module.
Optionally, when implementing the method of identifying an apparatus in a vehicle including a steering sensing arrangement for sensing a direction in which the vehicle is being steered, the method including steps of:                (a) communicating with one or more modules of the apparatus for receiving their identification codes (ID) at a processing arrangement of the apparatus, the one or more modules being mounted on at least one wheel of the vehicle;        (b) driving the vehicle around a curved trajectory as sensed by the steering sensing arrangement and recording an angle of steering of the vehicle together with a temporal record of pressures measured by the one or more modules together with their corresponding identification codes (ID), the pressure pertaining to one or more tires of the at least one wheel; and        (c) applying an analysis to the steering angle and the temporal record in respect of time to identify locations whereat the one or more modules are located on the at least one wheel of the vehicle, the analysis utilizing a characteristic that tires on an outside of the curved trajectory will experience greater pressure increases than tires on an inside of the curved trajectory, and that tires towards a front region of the vehicle experience an increase in pressure before tires towards a rear region of the vehicle for a forward direction of travel of vehicle.        
In this method the physical parameter is constituted by the pressure which is measured directly by a sensor in the module
Optionally, there is provided a method of identifying locations of one or more sensor modules of an apparatus implemented in a vehicle for monitoring operation of at least one wheel of the vehicle, the sensor modules operatively mounted to revolve with the at least one wheel, the one or more modules being operatively coupled in communication with a processing arrangement (ECU) of the vehicle, the one or more modules being operable to determine at least one physical parameter of the wheel and to generate at least one corresponding sensor signal for the processing arrangement, the processing arrangement (ECU) being operable to process the at least one sensor signal to compute information indicative of operation of the at least one wheel, characterized in that the method includes steps of:                (a) communicating with one or more modules (400) of said apparatus (680, 690, 2200) for receiving their identification codes (ID) at a processing arrangement (950) of said apparatus (680, 690, 2200), said one or more modules (400) being mounted on at least one wheel (10) of said vehicle (900);        (b) driving said vehicle (900) around a curved trajectory as sensed by a steering sensing arrangement and recording direction of steering of said vehicle (900) together with a temporal record of said angular velocity determined from a signal generated by said one or more modules (400) together with their corresponding identification codes (ID); and        (c) applying an analysis to said direction of steering and said temporal record in respect of time (t) to identify locations whereat said one or more modules (400) are located on said at least one wheel (10) of said vehicle (900), said analysis utilizing a characteristic that the angular velocity of a wheel located on an outside of said curved trajectory will experience greater magnitude during the curved trajectory in comparison to a the magnitude of the angular velocity of a wheel located on an inside of said curved trajectory, and that the angular velocity of a wheel located towards a front region of said vehicle (900) experience an increase in magnitude temporally before and/or at a higher rate than a wheel located towards a rear region of said vehicle (900) for a forward direction of travel of vehicle (900) during execution of said curved trajectory.        
In this method the physical parameter is derived from a sensor signal generated by a sensor in the module. Preferably the sensor may be an accelerometer arranged in each respective module, which accelerometer generates acceleration signal components in the tangential and/or radial direction (Ax, Ay)
In this method the step of identifying those one or more modules (400) mounted to a wall (230) or onto an inside rim of a tire (30) of the at least one wheel (10) is performed by identifying periodic pulses (500) in acceleration signal components (Ay, Az) derived from the one or more modules (400) corresponding to rotation of the at least one wheel (10)
Optionally, when implementing the method, the apparatus includes a sensor arrangement for sensing an angular orientation (□) of the at least one wheel.
Optionally, when implementing the method, the signals are indicative of at least one of:                (e) one or more components of acceleration (Ay, Ay) sensed at the at least one wheel; and        (f) a pressure sensed in a tire of the at least one wheel.        
Optionally, when implementing the method to provide pseudo-continuous monitoring or continuous monitoring of the at least one wheel, the method is implemented repetitively whilst the vehicle is being driven in normal use.
Optionally, when implementing the method, there is included an additional step after step (a) of identifying those one or more modules mounted to a wall or onto an inside rim of a tire of the at least one wheel by identifying periodic pulses in acceleration signal components (Ay, Az) derived from the one or more modules corresponding to rotation of the at least one wheel.
Optionally, when implementing the aforesaid methods of the invention, the one or more modules include a temperature sensor for sensing a temperature (Tmod) thereat, the one or more modules being operable to communicate a signal indicative of the temperature (Tmod) to the processing arrangement (ECU) for use in computing the information indicative of operation of the at least one wheel. Monitoring the temperature (Tmod) enables a pressure (P) measured within a tire of the at least one wheel to be at least partially corrected for temperature effects when executing computations regarding wheel operation. Moreover, in an event that an excessive temperature rise is detected, a warning can be optionally issued by the apparatus.
Optionally, when the aforesaid methods of the invention, the one or more modules include at least one of:                (a) a pressure sensor operable to sense a pressure (P) existing within a tire of the at least one wheel, the one or more modules being operable to communicate a signal indicative of the pressure (P) to the processing arrangement (ECU) for use in computing the information indicative of operation of the at least one wheel;        (b) a strain gauge sensor for measuring flexure of the tire of the at least one wheel, the module being operable to communicate a signal indicative of the flexure to the processing arrangement (ECU) for use in computing the information indicative of operation of the at least one wheel;        (c) an accelerometer for measuring acceleration (Ax, Ay, Az) in at least one axis at a mounting location (L1, L2, L3, L4) of the one or more modules on the at least one wheel, the one or more modules being operable to communicate a signal indicative of the acceleration (Ax, Ay, Az) to the processing arrangement (ECU) for use in computing the information indicative of operation of the at least one wheel; and        (d) a magnetic sensor for measuring a magnetic field applied to the one or more modules, the one or more modules being operable to communicate a signal indicative of the applied magnetic field to the processing arrangement (ECU) for use in controlling operation of the apparatus.        
Such physical parameters have been found to be beneficial to monitor when assessing operation of the at least one wheel. It will be appreciated that the one or more modules can be equipped with a subset of the options (a) to (d); for example, a module can be provided with only a pressure sensor, or only an accelerometer, or a combination of a pressure sensor and an accelerometer depending upon which method of aforesaid aspects of the invention are to be employed. Moreover, certain modules are optionally provided with only a single-axis accelerometer, whereas other such modules are provided with triple-axis accelerometers. Other combinations of sensors included within the modules are possible pursuant to the present invention.
More optionally, when implementing the method, the accelerometer is a multi-axis accelerometer operable to measure components of acceleration (Ax, Ay, Az) in at least one of radial, tangential and transverse axes in respect of rotations of the at least one wheel. Yet more optionally, the accelerometer is a silicon micromachined device. Such silicon devices are extremely robust, cost effective and are capable of providing precise and accurate measurement of acceleration.
Optionally, when implementing the method when accelerometers are employed, the processing arrangement (ECU) is operable to apply auto-alignment to one or more sensing axes of the accelerometer to effectively align them to at least one of radial, tangential and transverse axes in respect of rotations of the at least one wheel. Such auto-alignment is capable of simplifying installation of the one or more modules by rendering placement of the one or more modules on the at least one wheel less angularly critical.
More optionally, when implementing the method, the processing arrangement (ECU) includes an angular resolver for implementing the auto-alignment which is operable to seek during its calibration to null lateral acceleration components and to seek to null tangential acceleration components integrated over one or more complete revolutions of the at least one wheel. By applying such auto-alignment, more representative signals describing operation of the at least one wheel are derivable for the processing arrangement to analyse. Optionally, acceleration measurements can be implemented for a part of a revolution, for example a half-revolution, of the at least one wheel and the measurements for a remaining half-revolution of the at least one wheel synthesized therefrom for integration purposes; such an implementation is to be construed to mean integration for a complete revolution of the wheel.
Yet more optionally when implementing the method, the processing arrangement (ECU) is operable to calibrate its auto-alignment during at least one of:                (a) a calibration procedure when configuring the processing arrangement (ECU) in relation to its one or more modules; and        (b) in a dynamic manner during driving of the vehicle.        
Optionally, when implementing aforementioned methods of the invention, the one or more modules are mounted at one or more locations (L1, L2, L3, L4) on the at least one wheel, the one or more locations including:                (a) on a hub of the at least one wheel substantially at an axis (B-B) of rotation of the at least one wheel;        (b) on a hub of the at least one wheel at a radial distance from the axis of rotation (B-B) of the at least one wheel;        (c) within a tire of the at least one wheel for sensing a pressure (P) within the tire, the at least one module being mounted to a peripheral surface of a hub of the at least one wheel;        (d) within a tire of the wheel for sensing a pressure (P) within the tire, the one or more modules being mounted to an inside side-wall surface of the tire for measuring flexural characteristics of the side-wall; and        (e) on an inside surface of a peripheral rim of the at least one wheel for measuring acceleration thereat.        
Mounting the one or more modules at these different locations is of benefit in that certain types of defect in the at least one wheel are more reliably sensed when the one or more modules are mounted at specific favourable locations. For example, wheel imbalance is better sensed with a module mounted on the wheel near its hub, whereas flexural characteristics of the tire or inflatable cavity are better sensed with a module attached to a side wall of the tire or flexible inflatable cavity. More optionally, a module is mounted to an inside rim of a tire, adjacent to its treads (L4).
Optionally, when implementing aforementioned methods of the invention, the one or more modules include at least one wireless interface for communicating between the one or more modules and the processing arrangement (ECU), the one or more modules forming a wireless network wherein certain of the one or more modules are operable to function as one or more relay nodes for conveying signal exchange between the processing arrangement (ECU) and other of the one or more modules. By establishing such a communication network, modules mounted in wireless shadows where they are occluded by conductive elements are operable, via the network, to provide their measured signals to the processing arrangement.
Optionally, when implementing aforesaid methods of the invention, the one or more modules include at least one wireless interface for communicating between the one or more modules and the processing arrangement (ECU), the one or more modules forming a wireless network which is dynamically reconfigurable for conveying signals between the one or more modules and the processing arrangement (ECU). An ability exhibited by the network to dynamically reconfigure itself is of advantage in that the apparatus is able to continue operating with reduced monitoring functionality in an event of one or more of the modules ceasing to provide their respective signals to the processing arrangement (ECU). Such a reconfigurable property of the network not only renders the apparatus more robust, but also allows the apparatus to adapt when additional modules are added to the apparatus, for example in response to changing one or more of the wheels.
Optionally, when implementing aforementioned methods of the invention, the one or more modules include at least one wireless interface for communicating between the one or more modules and the processing arrangement (ECU), the one or more modules forming a wireless network which is dynamically reconfigurable in response to the one or more modules changing between functional and non-functional states in operation, for enabling the apparatus to continue functioning with modified functionality in respecting of monitoring operation of the at least one wheel. Such an operating characteristic circumvents the apparatus becoming non-function merely on account of one of its modules developing a problem in operation, for example its battery becomes fully discharged in operation.
Optionally, when implementing the aforesaid methods of the invention, the one or more modules are each provided with a corresponding identification code (ID) for communicating to the processing arrangement (ECU) so that the processing arrangement (ECU) is able to recognize from which module corresponding signal data has been sent. Use of such identification codes (ID) enables one or more wheels which have developed problems, or have been found to have potential problems, to be clearly identified and a corresponding unambiguous informative warning sent to the driver of the vehicle and/or to a service facility responsible for addressing such problems or potential problems.
Optionally, when implementing the aforementioned methods of the invention, the one or more modules include one or more sources of electrical power for energizing the one or more modules, the one or more sources of electrical power including at least one rechargeable battery and one or more generators for recharging the one or more sources, the one or more generators deriving energy from rotations of the at least one wheel. More optionally, the one or more generators are at least one of:                (a) an electromagnetic generator based upon movement of a mass operable to move in response to rotations of the at least one wheel; and        (b) a piezo-electric generator based upon force generated by a mass operable to apply a varying force to a piezo-electric device in response to rotations of the at least one wheel.        
On account of the one or more modules rotating with their respective wheels, providing electrical slip rings or inductive electrical couplings represents a considerable practical complication, especially in view of regions around wheels of contemporary wheels already being heavily populated with other components such as ABS rotation sensors, disc brakes, suspension components and so forth. However, after prolonged use, local sources of power can become exhausted unless recharged or replaced; inclusion of the one or more generators are capable of addressing such problems.
In order to gather more representative measurements indicative of operation of the at least one wheel, the wheel-monitoring apparatus is optionally implemented such that the one or more modules are radially distributed around the at least one wheel for sensing operation of the at least one wheel at a plurality of angular locations therearound.
Certain conductive components in and around the at least one wheel are susceptible to creating radio shadows and causing Faraday screening. In order to address problems arising from such radio shadows and Faraday screening, in the wheel-monitoring apparatus, at least one of the one or more modules optionally includes a wireless interface coupled to an electrically conducting mesh of a tire of the at least one wheel, the conducting mesh being operable to function as a wireless patch antenna for the at least one module for supporting wireless communication between the at least module and the processing arrangement (ECU).
Optionally, aforesaid methods of the invention include a step of presenting information to a driver of the vehicle on a display coupled in communication with the processing arrangement (ECU), the information indicating at least one of:                (a) an operating status of the one or more modules;        (b) a condition of the at least one wheel;        (c) one or more faults or potential faults associated with the at least one wheel;        (d) information regarding one or more actions to be taken by a driver of the vehicle in an event of one or more faults or potential faults associated with the at least one wheel being identified; and        (e) an indication of whether or not at the at least one wheel of the vehicle has been modified, for example tampered with.        
The display is however not limited to displaying such information as in (a) to (e) and is optionally capable of presenting other analysis information provided from the processing arrangement, for example a time record of changes in one or more wheel parameters as sensed by the one or more modules; for example, the display can beneficially present a graph representing tire pressure as a function of time, a list describing a configuration of modules presently coupled in communication with the processing arrangement, and so forth.
Optionally, the aforesaid methods of the invention include a step of providing the processing arrangement (ECU) with a wireless interface for communicating with a service facility remote from the vehicle, the processing arrangement (ECU) being operable to communicate information indicative of functionality of the at least one wheel, the information being indicative of one or more faults or potential faults associated with the at least one wheel as computed from signals provided from the one or more modules, and for receiving instructions from the service facility regarding actions for addressing the one or more faults or potential faults.
More optionally, the aforesaid methods of the invention include a step of providing the vehicle with a global positioning unit for generating a signal indicative of a spatial position of the vehicle, and for conveying information via the processing arrangement (ECU) to the wireless interface to the service facility indicative of the spatial position of the vehicle.
Optionally, when implementing the aforesaid methods of the invention, the one or more modules include a processor coupled to an associated data memory, the one or more modules via their pressure sensors being operable to record a pressure (P) within a tire of the at least one wheel in relation to time (t) as determined by a clock arrangement (CLK) included within the one or more modules, and the processor is operable to monitor changes in the pressure (P) with time (t) to identify one or more of:                (a) a gradual leak of air or gas from the tire indicative of a need to recharge the tire with air or gas; and        (b) any abrupt depressurization of the tire indicative of a puncturing or rapid deflation event having occurred, or the tire having been exchanged.        
More optionally, the one or more modules are operable to communicate to the processing arrangement a message that sensed data pertaining to the tire of the at least one wheel being potentially unreliable due to the abrupt depressurization, for example due to a tampering event. Such processing is useful for detecting events, for example unauthorized swapping of tires, occurring when an associated wheel is temporarily dismantled from the vehicle and outside a wireless communication range of the processing arrangement (ECU). Generation of such a message is useful for enhancing safety; unauthorized or unintentional swapping of a tire or wheel of the vehicle can potentially contribute to safety risks or degraded reliability about which the driver of the vehicle is beneficially informed.
Optionally, when implementing the aforesaid methods of the invention, the one or more modules are operable to monitor the pressure (P), irrespective of whether or not the one or more modules are in their hibernating energy-saving state. Such operation renders tampering executed on the vehicle when in a parked state detectable.
Optionally, when implementing the aforesaid methods, the one or more modules are operable to switch between an active state and an energy-saving hibernating state. The hibernating state is of benefit in that it prolongs a period of use of the batteries associated with the one or more modules and renders frequent recharging of the batteries less necessary thereby prolonging their operating lifetime. Rechargeable batteries are only capable of withstanding a finite number of discharge cycles before their electrical storage capacity deteriorates.
More optionally, when implementing the methods, the one or more modules are operable to switch between the active state and the hibernating state in response to one or more instructions communicated by wireless to the one or more modules. By using such wireless instructions, it is feasible to force all the one or more modules into their hibernating state promptly after, for example, parking the vehicle and switching-off its combustion engine; the hibernating state conserves energy in batteries of the one or more modules when the vehicle is not in use. Likewise, a single wireless instruction is capable of waking up the one or more modules from their hibernating state when the vehicle is started again.
Yet more optionally, when implementing the methods, the one or more modules are operable to switch from the active state to the energy-saving hibernating state in response to a period of time (t) in which the one or more modules detect one or more of:                (a) a cessation of changes in pressure (P) of a tire of the at least one wheel during a predetermined period of time (t); and        (b) a cessation of changes in acceleration (Ax, Ay, Az) sensed on the at least one wheel during a predetermined period of time (t).        
More optionally, the one or more modules are operable to switch from the energy-saving hibernating state to the active state in response to the one or more modules detecting one or more of:                (a) a resumption of changes in pressure (P) of a tire of the at least one wheel associated with rotations of the at least one wheel; and        (b) a resumption of changes in acceleration (Ax, Ay, Az) sensed on the at least one wheel.        
Similarly, the one or modules are beneficially capable of automatically and autonomously returning to their active state without the processing arrangement needing to send any explicit instructions.
Optionally, when implementing aforesaid methods of the invention, the at least one physical parameter includes at least one of:                (a) a pressure (P) within a tire of the at least one wheel as measured at the one or more modules;        (b) an acceleration (Ax, Ay, Az) as measured substantially at the one or more modules; wherein the processing arrangement (ECU) is operable to apply an harmonic analysis to signals corresponding to the pressure (P) and/or the acceleration (Ax, Ay, Az), the harmonic analysis being operable to identify harmonic components in respect of angular frequency (□) corresponding to a temporal rate of change of the angular orientation (□) of the at least one wheel. Certain problems or potential problems are susceptible to being identified merely by processing magnitudes of the harmonic components, whereas detection of flexural problems beneficially requires analysis of both harmonic magnetic and relative harmonic phase data in the processing arrangement; see FIG. 10 for example regarding skewing of presented peaks on account of changes in relative phase in harmonic components identified by the processing arrangement.        
More optionally, when implementing the present invention, the harmonic analysis applies computation to at least one of:                (a) magnitudes of the harmonic components; and        (b) relative phase relationships between the harmonic components.        
More optionally, when implementing the present invention, the processing arrangement (ECU) is operable to employ the harmonic analysis for identifying an occurrence of at least one of:                (a) the at least one wheel is imbalanced;        (b) a specific type of imbalance is present in the at least one wheel;        (c) the at least one wheel is skewed in relation to its axle;        (d) the at least one wheel is loose and wobbling about on its fasteners;        (e) a tire of the at least one wheel has defects in its flexural characteristics;        (f) a tire of the at least one wheel is insufficiently inflated;        (g) a tire of the at least one wheel is over inflated;        (h) a tire of the at least one wheel is oval or has a higher-order lobed distortion;        (i) the at least one wheel has a mass imbalance therein; and        (j) wheel bearings associated with an axle rotationally supporting the at least one wheel in operation are vibrating or rattling in an unexpected manner indicative of a fault, or a potentially developing fault.        
The processing arrangement is not limited to detecting problems (a) to (j) above and is capable of detecting other problems, for example rattling noises in bearings associated with an axle of the wheel as manifested in acceleration or acoustic sensed signals at the one or more modules.
More optionally, when implementing methods of the invention, the processing arrangement (ECU) is operable to perform the analysis of the harmonic components by applying:                (a) a rule-based algorithm for identifying one or more faults or potential faults from the harmonic components;        (b) a neural network pre-programmed to identify one or more faults or potential faults when presented with data describing the harmonic components; and/or        (c) an harmonic filter for highlighting a specific combination of one or more harmonic components which are indicative of one or more faults or potential faults with the at least one wheel.        
Other approaches to harmonic component analysis can optionally also be employed in the apparatus.
Optionally, when implementing aforesaid methods of the present invention, there is included a step of providing the processing arrangement (ECU) with a predetermined list of types of wheel susceptible to being employed with the vehicle and associated expected characteristics, and the one or more modules are operable to communicate information to the processing arrangement (ECU) regarding an identification of a type of wheel onto which the one or more modules are mounted, and the processing arrangement (ECU) is operable to compare measured signals provided from the one or more modules with signals that would be expected from the one or more modules as simulated from the predetermined list, and wherein a disparity between the measured signals and the simulated signals is indicative of one or more faults or potential faults. Such an approach is susceptible to avoiding a need to perform an harmonic analysis and therefore is computationally less intensive for the processing arrangement.
Optionally, when implementing aforesaid methods, the one or more modules include one or more processors therein, and computation effort executed in operation for identifying one or more faults or potential faults in the at least one wheel is shared between the one or more processors and the processing arrangement (ECU). Optionally, computational load within the vehicle is distributed so as to avoid causing data processing overload at the processing arrangement, especially when many of the modules are included on wheels of the vehicle.
Optionally, in the aforementioned methods, the processing arrangement (ECU) is operable to send a message requesting the one or modules to respond back to the processing arrangement (ECU) for declaring their identification codes (ID) to the processing arrangement (ECU) for enabling the processing arrangement to identify its configuration of one or more modules, and for identifying any changes in the configuration of one or more modules occurring. More optionally, the one or more modules are operable to also respond with data indicative of expected characteristics of the at least one wheel to which the one of more modules are mounted in order that the processing arrangement is operable to perform a correct monitoring of wheels of the vehicle, it requires a recent list or record of modules present on the wheels.
Optionally, when implementing the aforesaid methods, the processing arrangement (ECU) is operable to compare rotation measurements from the sensor arrangement for sensing the angular orientation (□) of the at least one wheel against signals supplied from the one or more corresponding modules for checking functional operation of the sensor arrangement and/or the one or more modules. More optionally, the sensor arrangement is an ABS wheel angular orientation sensor associated with brakes of the vehicle. Operational integrity the wheel-monitoring apparatus is desirable so that detection of problems and potential problems is as effective as possible. Optionally, so as to obtain greater functionality from existing components already included on the vehicle, when implementing the wheel-monitoring apparatus, the sensor arrangement is an ABS wheel angular orientation sensor associated with brakes of the vehicle.
According to a second aspect of the invention, there is provided a wheel-monitoring apparatus operable to execute a method pursuant to at least one of the first, second and third aspects of the invention.
According to a third aspect of the invention, there is provided a module operable to function in a vehicle for implementing a method pursuant to at least one of the first, second and third aspects of the invention.
According to a fourth aspect of the invention, there is provided a vehicle including a wheel-monitoring apparatus pursuant to the fourth aspect of the invention, the apparatus being operable to monitor operation of at least one wheel (10) of the vehicle (900) pursuant to a method of at least one of the first, second and third aspects of the invention.
Optionally, the vehicle is at least one of: a heavy commercial vehicle, a construction vehicle, an automobile, a motorcycle, a scooter, an aircraft, a helicopter, a bicycle.
According to a fifth aspect of the invention, there is provided a wheel including one or more modules mounted thereonto, the one or more modules operable to function with a wheel-monitoring apparatus pursuant to the fourth aspect of the invention operable to monitor operation of at least one wheel of the vehicle pursuant to at least one of the first, second and third aspects of the invention.
According to an sixth aspect of the invention, there is provided a tire including a module as pursuant to the fifth aspect of the invention.
Optionally, the module is mounted to a side wall or adjacent a thread-section of the tire.
When the aforementioned apparatus has been “calibrated” pursuant to at least one of the first, second and third aspects of the invention, namely positions of one or more modules identified, the apparatus is operable to provide wheel and tire monitoring. An additional technical problem then pertains how best utilize information provided from the apparatus for maintaining the vehicle operational in service.
This additional technical problem is at least partially addressed by the present invention.
According to a seventh aspect of the present invention, there is provided a system including one or more vehicles, wherein each vehicle includes a wheel-monitoring apparatus operable to execute a method pursuant to at least one of the first, second and third aspects of the invention, the system comprising:                (a) a control centre for coordinating repair or maintenance of the one or more vehicles;        (b) one or more service facilities operable to perform repair or replacement on the one or more vehicles; wherein the system is operable to:        (c) enable each wheel-monitoring apparatus to monitor operation of its one or more associated wheels and detect when a problem or potential problem arises therewith;        (d) enable each wheel-monitoring apparatus to communicate the problem or potential problem to the control centre, for the control centre to identify one or more service facilities capable of addressing the problem or potential problem; and        (e) enable the control centre to communicate instructions to the one or more vehicles whose wheel-monitoring apparatus has detected a problem or potential problem to the identified one or more service facilities for the problem or potential problem to be addressed.        
Optionally, the system in (e) is operable to inform the identified one or more service facilities in advance of arrival of the one or more vehicles for maintenance or repair, so that the identified one or more service facilities are provided with an opportunity to make preparation for arrival of the one or more vehicle for maintenance or repair.
Optionally, when implementing the system, the control centre is operable to organise the maintenance or repair at the identified one or more service facilities automatically without one or more drivers of the one or more vehicles needing to intervene.
Optionally, in the system, the one or more vehicles include global position sensing apparatus thereon coupled in communication with the wheel-monitoring apparatus for enabling the one or more vehicles to communicate their position to the control centre, so that the control centre is operable to identify one or more service facilities most suitably geographically disposed to service the one or more vehicles.
According to a eight aspect of the invention, there is provided a method of operating a system including one or more vehicles, wherein each vehicle includes a wheel-monitoring apparatus operable to implement a method pursuant to the present invention, the system comprising:                (a) a control centre for coordinating repair or maintenance of the one or more vehicles;        (b) one or more service facilities operable to perform repair or replacement on the one or more vehicles;wherein the method includes steps of:        (c) enabling each wheel-monitoring apparatus to monitor operation of its one or more associated wheels and to detect when a problem or potential problem arises therewith;        (d) enabling each wheel-monitoring apparatus to communicate the problem or potential problem to the control centre, for the control centre to identify one or more service facilities capable of addressing the problem or potential problem; and        (e) enabling the control centre to communicate instructions to the one or more vehicles whose wheel-monitoring apparatus has detected a problem or potential problem to the identified one or more service facilities for the problem or potential problem to be addressed.        
According to an ninth aspect of the invention, there is provided a software product recorded on a data carrier, the product being executable on computing hardware for executing a method pursuant to the present invention.
Features of the invention are susceptible to being combined together in any combination without departing from the scope of the invention as defined by the appended claims.